Engine - Intake Manifold Bolt Usage
TA03 1202April 3, 2003
ATTENTION:
Service Manager
Service Advisor
Technician
Land Rover V8 Manifold Bolt Re-Use
TIB 12/02/99/NAS "Intake Manifold Gasket Leaks" identified a new grade of bolt to be used when reinstalling intake manifolds that had been diagnosed as leaking on a specific range of 1999 Discovery and Range Rover vehicles. This bulletin does NOT apply to all vehicles and should not be interpreted as requiring the replacement of intake manifold bolts on all vehicles under repair.
NOTE:
Manifold bolts used to secure the intake manifold to the 4.0 and 4.6 liter Land Rover V8 engines are currently experiencing a very high demand. Since "V" specification bolts have been used as repair components on early vehicles for several years now, and also in production since 1999 Land Rover expects that some portion of this demand may be unnecessary.
Manifolds secured by "V" grade bolts may have those bolts re-used. The new specification bolts announced in TIB 12/02/99/NAS (LYG101450 and LYG101440) are identified by a "V on the bolt head. They will not experience the "stretching" that was the root cause of some manifold leaks. The only requirement for reuse is that a thread sealant be applied to the threads before installation and performance of the torque procedures.
1. Refer to WSM 12-2-43 and install "V" specification bolts taking note of the following care points:
^ If old "V" grade bolts are to be reused, clean and remove oil and sealant residue from bolts
^ Apply sealant to bolt threads
^ Install long bolts (LYG101450) in the two front-most locations (Positions 10 and 11, Figure 1).
^ Install shorter bolts (LYG101440) in the remaining locations.
^ Refer to the Workshop Manual and follow the proper torque sequence and value when installing the bolts.